6720191 has 2 divisors, whose sum is σ = 6720192. Its totient is φ = 6720190.

The previous prime is 6720179. The next prime is 6720227. The reversal of 6720191 is 1910276.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6720191 is a prime.

It is a Chen prime.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 6720191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6720691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3360095 + 3360096.

It is an arithmetic number, because the mean of its divisors is an integer number (3360096).

Almost surely, 2^6720191 is an apocalyptic number.

6720191 is a deficient number, since it is larger than the sum of its proper divisors (1).

6720191 is an equidigital number, since it uses as much as digits as its factorization.

6720191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 6720191 is about 2592.3331190262. Note that the first 3 decimals coincide. The cubic root of 6720191 is about 188.7095470520.

The spelling of 6720191 in words is "six million, seven hundred twenty thousand, one hundred ninety-one".